Roll of Honor
Incident
Patrolman Martin O'Brien and Patrolman Francis Mulvihill were shot and killed at approximately 11:15 p.m. by four men believed to be part of the Dillinger Gang. The officers were patrolling a rural section of the old Gary Road when they stopped to talk with four men standing next to a car. Without warning, the suspects opened fire with machine guns, striking both officers multiple times. The suspects then fled the scene. Patrolman Mulvihill was to be the witness against John Dillinger for the killing of Patrolman William Patrick O'Malley. Patrolman O'Brien had served with the East Chicago Police Department for nearly 14 years. He was survived by his wife and three children. Led by John Dillinger, the Dillinger Gang was a notorious group of Midwest bank robbers. Associates of the gang were responsible for the fatal shootings of 13 law enforcement officers in 1933 and 1934. Two infamous members of the gang, John Dillinger and Baby Face Nelson, were shot and killed by law enforcement officers in separate incidents. The other gang members were either murdered by criminals, shot and killed by law enforcement officers, executed for their crimes, or sentenced to time in prison. Click here to see all the officers killed by members of the Dillinger Gang
Survivors
He was survived by his wife and three children.
In Our Keeping
- Permanent identifier
BO-US-IN-136B063B- Stewardship
- Maintained by NeuraWeb Global Inc.
- Added to badge.nw
- April 2, 2026
- Last updated
- July 23, 2026
Honored here by 1 sentinel - 1 tribute.
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Tributes
I never knew you. I am standing here anyway.
Patrolman O'Brien gave the East Chicago Police Department 13 years.
Thank you for your service to the East Chicago community. Gone but never to be forgotten.
Rest easy, Patrolman O'Brien.
— S. Vincent Anthony, U.S. Army 1985-1993
Agency
Service Record
Incident Details
Patrolman Martin J. O'Brien is one of 17,623 officers killed feloniously — deliberately targeted and murdered in the line of duty across the full record of this memorial — 54.2% of all 32,508 officers honored here.
In IN, 311 of 503 officers were killed feloniously — deliberately targeted and murdered in the line of duty — 61.8% of this state's fallen. That is 7.6 percentage points above the national rate of 54.2%.
At East Chicago Police Department, 8 of 8 officers on record were killed feloniously — deliberately targeted and murdered in the line of duty — 100% of this agency's fallen.
National Cause Distribution
How Felonious compares to all causes of officer death in the memorial record. Martin J. O'Brien's cause is highlighted.
How Martin J. O'Brien Compares
Offender Outcome
The Dillinger Gang
When Felonious Deaths Occur
Monthly distribution of Felonious deaths across the full memorial record. Martin J. O'Brien is highlighted in May.
Weapons Used Against Officers
Most common weapons in felonious officer deaths. Martin J. O'Brien was killed by rifle; machine gun.
Others Who Wore This Badge
7 officers from East Chicago Police Department are honored on badge.nw.
